BAPI有的是类，有的是函数。'Business application programming interface'的简称。

BAPI is 'Business application programming interface', similar to API. which are
stable, standardized methods to access data in R/3

To use BAPIs to access SAP business objects you will need a good understanding of
object-oriented programming. You should also have a basic knowledge of the R/3
System.

BAPIs can be accessed from various programming environments, for example,
Delphi/Connect from Inprise (formerly Borland), Microsoft’s Visual Studio, C++ and
Java platforms. You must be familiar with the development environment used to access
BAPIs.

BAPIs are available from development platforms external to R/3 that support the
Remote Function Call (RFC) protocol. If you are developing your application in a non-
object oriented programming language, you need to have RFC programming skills to
call BAPIs via RFC. In particular, you need to know how to perform RFC calls.